A Primer On Pain

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Pain is a necessary, complex, and unique experience that is different for everyone and every instance.

Pain can no longer be thought of strictly in terms of biomechanics and tissue damage.

Pain is an output from the brain intended to get you to take action and mitigate a threat.

Taking a biopsychosocial approach can help you recognize factors other than biomechanics that can contribute to the pain experience.

Don’t forget the “bio,” but make room for the other parts.

Introducing pain science concepts can be very powerful and may help to assuage fears and decrease anxiety.

Normalize their experience, inspire positivity, and get your patients moving!

Thinking, Reasoning, And Emotional Brains

I was discussing this post with a coworker and I told him what this was going to be about. Here is how he said he explains pain to his patients:

“It hurts.”

Absolutely enthralling. Captivating actually. Apparently it should be a pretty short post. Two word max. I would really have to mess with the font and the margins to meet the page count here. Some therapists are not hip to the pain science jive and while he was joking, this may be indicative of the average therapist in an outpatient setting. I think I can do better. In the foreword of “Therapeutic Neuroscience Education: Teaching Patients About Pain” by Adriaan Louw and Emilio Puentendura, Louis Gifford, a physiotherapist, writes:

“Remember, every pain problem, acute or chronic, has a thinking, reasoning, and emotional brain attached to it.” (2013, p. v)

The biopsychosocial model of disability was a bit of an inside joke in school. Just saying “biopsychosocial” or “ICF model” around some of my friends still elicits a few groans. We had jokes about it in serious presentations. Most of our classes were focused on the “bio” part of it. We were memorizing muscles, bones, and nerves, perfecting intricate manual techniques, or coming up with creative exercises for any given impairment. We would spend entire labs analyzing the gait of our classmates, picking apart the posture of a teaching assistant, or watching our professors perform manual techniques some of us may never use. We are supposed to be the experts of movement and exercise after all. It would make sense to spend the most time on that. It is easy to get lost in seemingly sophisticated biomechanical minutiae. I know, because I was lost in it for a bit. I wanted to be that manual therapist/expert biomechanist/super smart guy. The “psycho” and the “social” portions got less attention. Some, but probably not enough.

We need to be able to connect and empathize with other humans, especially when it comes to understanding the experience of pain and how it affects a person. Pain is more complex than we learned.

Sure, you can rate it on a scale of 0 to 10. You can describe the pain’s quality, its location, and what makes it better or worse. You might even be able to recite typical types of complaints for any given diagnosis. However, there is more to the story than the VAS, pain diagrams, or those pesky “pain fibers.” According to the International Association for the Study of Pain, the definition of pain is:

“An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.”

There are a few keywords in there, namely “experience,” “emotional,” and “potential.” There are other factors that play a role in a person’s experience with pain, particularly, the circumstances around which it has arisen, physical modulators like inflammation, or any psychosocial issues they may have like anxiety or depression (Moseley, 2007, p. 170). Fear of movement and catastrophizing play a role as well (Louw, 2013, p. 17). We have a much better understanding of pain these days, thanks to physiotherapists Lorimer Moseley, David Butler, Adriaan Louw and their colleagues, and there are important implications for how a therapist should treat it.

New Perspectives On Why Pain Hurts So Much

Pain was thought to be straightforward. You step on a rusty nail, that nail sets off nociceptors in your poor bleeding foot, and you get that “unpleasant sensory and emotional experience.” Presumably, you stop stepping on all those rusty nails all the time. Why would you step on nails so often anyway, you savage. We don’t want to step on sharp things because they will cause damage to our precious feet. Feeling pain is for your protection, and is a normal and necessary part of life (Butler, 2013, p. 10-11). Your body just wants to protect you from harm, and most of the time it does a good job. But, much like all the other systems in your body, sometimes things can go awry. Sometimes, things don’t always add up. People you think “should” be in pain feel nothing, and people that “should” have no pain continue to feel it. Someone can be sitting next to you calmly describing what is going on, and tell you they have 10/10 pain. It is frustrating to deal with these patients because biomechanical explanations stop working. You might even think these patients are being dramatic, emotional, or are just trying to get attention. What else could be going on?

Lorimer Moseley lays out the case for reconceptualising pain in the aptly named “Reconceptualising Pain According to Modern Pain Science.” He writes pain can be thought of as

According to Moseley and his colleagues, pain is part of a multi-system output of the brain, based on all the available information it has, including input from the tissues, beliefs and attitudes, and the context of the situation, in order to get you to act in a specific way, like not stepping on rusty nails anymore, or not letting your back bend forward. Just like sight is the conscious experience of the receptors in your eye, afferent nerves, and different locations in the brain, formulated to help you be a successful human (in the darwinian evolutionary sense), pain is the conscious experience that helps you avoid physical and emotional threats. Pain is your handy alarm system, letting you know when something is a threat, and action is needed (Louw, 2013, p. 119).

Neither Sufficient Nor Necessary?

What threats does the brain have to consider? As Butler and Moseley put it simply in Explain Pain:

If nociceptive input was the only factor the brain considers when deciding if pain would be a useful experience for a person, then presumably anyone with tissue damage would have pain. We know from various imaging studies (Haig et.al. 2006, Takatalo et.al. 2011, Gill et.al. 2014, Brinjikji et.al. 2015, Schwartzberg et.al. 2016, I am sure there are more), patients can have some ugly x-rays or MRIs but be asymptomatic. Some of these studies show no relationship between pathoanatomy and pain, some show some correlation, and some even show a high correlation. Even in the studies that have a high correlation between what is found on imaging and pain, there is a some significant portion of the population that is asymptomatic but has positive findings. Moseley rightly concludes that pain cannot be a completely accurate gauge of the state of the tissues (2007, p. 170). I am sure you have seen patients that present with pain that is more or less what you would expect for the average person. Nociceptors do not send messages about pain, just messages about what is going locally in the tissues.

It follows from the previous point that nociception (what is going on in the tissues) is but one of many inputs the brain has to consider when deciding on an output of pain. If pain is the brain’s way of protecting you, it follows that your brain should be as vigilant as possible and thus consider as many factors as possible. Many things can modulate pain including the context of the situation, psychological factors like anxiety or depression, the time over which the injury has occurred, a person’s beliefs about pain, medical treatment, exercise, etc, kinesiophobia, other physiological processes going on, or social and cultural factors (Butler, 2013). These other factors can be the subject of many more blog posts.

Jacking In To The (Neuro)Matrix

Because we need to consider everything that is happening, the experience of pain involves multiple systems throughout the body. Peripheral nerves send their input up through the spinal cord, a modulator of these signals, and then up to the brain where a constellation of areas are activated. According to Butler and Moseley, many different areas of the brain light up with activity when a person is experiencing pain including the motor cortex, the amygdala, the sensory cortex, the thalamus, the cerebellum, and the hippocampus (2013, p. 39).

If pain is our body’s response to a threat, it would make sense that it would activate all these areas to change our behavior, mitigate current threats, and reduce future ones. We might move differently, or move more carefully. We might hold muscles really tight to prevent the joint from moving at all. We might form a memory of the experience in order to have more information on future threats. We might even start to associate fear with specific movements in order to deter moving in those ways. When complex behaviors are required to deal with threats, we need multiple systems to work together to do it. This is what is termed as a nuerotag and sometimes a neuromatrix: a specific constellation of neural activity a person has when experiencing pain that is always unique to the individual’s specific pain experience (Butler, 2013, p. 38). Most of the time, this system works great. Other times, things can go off the rails.

Talking To Patients About Pain When You Are A New Grad

Having conversations with patients about pain can be difficult as a new graduate. I’m just a lowly graduate student with a few opinions. Things are generally stacked against us here. Our programs are probably not caught up with the research. We don’t have a class on pain and it is often merely discussed in reference to specific conditions and patterns that are commonly seen. Many therapists I have worked with stick to seemingly sophisticated and often tenuous biomechanical explanations that can scare patients and send the wrong messages. They are broken, they need fixing, and they need a therapist with magic hands to do it. Patients are out of alignment, their cores are weak, they have no stability, their posture is awful, and they are just so tight everywhere. We scare patients too often, and that can feed into patients’ beliefs about themselves, their body, and exercise. I have seen this first hand.

One patient I worked with told me her doctor insisted that she was going to have pain and it was only going to get worse, based on her x-rays of her knees and her “bowleggedness.” Her x-rays showed that her knees were “bone on bone” and she made sure to tell me three to four times on the evaluation and at least once on every subsequent appointment. She even said she wasn’t expecting any improvement because afterall, she was bone on bone. Another patient I worked with was told that she wasn’t allowed to exercise by herself because she was going to hurt her back. I thought it was a joke. “Ha ha,” I said. “It’s not a joke” she said. Her therapist told her she really shouldn’t be doing anything by herself.

Another patient was not allowed to do anything, like running on a treadmill, doing a dynamic warm-up or basic strengthening exercises, without having a towel under his chin to prevent any cervical extension. I constantly hear therapists say “that’s awful for you,” or “don’t ever do that.” I have seen friends and colleagues wince and gasp at a person’s genu recurvatum, pes planus, or tight upper traps. While I don’t mean to disparage these therapists, because I work with extremely smart, passionate, and caring people, I think we can do better than this. We don’t have to contribute to patients’ fears and negative perceptions of their body and of exercise in general. I think being positive, encouraging, and hopeful for our patients is something that should be easy and come naturally. Actually talking about pain and what it means is part of that.

Most of my conversations about pain start with “…yeah, pain can be funny like that sometimes.” A lot of times, patients will just ask the right questions.

“Why does it hurt on the first rep but gets better after?”

“Sometimes my pain has no pattern, and I see no reason why I would flare-up, why is that?”

“Why is my pain worse when I am stressed?”

“Why does bending my knee just a little bit hurt so much?”

In my experience, patients with acute problems don’t really have these questions too often. Some concepts are useful, but more often than not, things go swimmingly. For patients who have gone chronic or patients that have had a traumatic accident or surgery, they come up quite a bit. I do my best to answer these questions based on the research and what I have read. A lot of times these explanations click with people. It resonates because it validates their experience, explains something mysterious, and provides hope. Chronic pain does not mean a person’s body is destroyed and there is no opportunities for change or chances to recover. The patients who I have had these talks with are more ready to exercise, try new things, and push themselves a bit more. Obviously, this is anecdotal, but there is some evidence for it.

If you are a physical therapist, you should care about this! Patient education can have a profound impact. Our words have meaning and importance. Patients will value our input and if we are consistently positive, honest, and educational, we can make relevant and meaningful changes. It is our duty to be up on the science and deliver this information effectively to our patients. Anything less would be a disservice to the people we got in this profession for.

To Conclude…

What I have read about pain clarifies a lot of things, but also adds more questions. There are studies I have not read yet, and concepts we still do not understand. We are still learning about pain and its implications for treatment and there is plenty more for me to unpack in future posts. The information here may not drastically change what you do for treatment, but it should change the way you look at a patient and the way you talk to them. As new members in the healthcare world, we are in a unique position. We are clinicians that are experts in exercise and movement and we can actually spend more than five minutes with a patient. We are in a perfect position to educate our patients on pain and get them moving again. Many of our patients have had chronic pain for a long time, have seen multiple healthcare practitioners, and have been little miniature science experiments for the latest panacea in healthcare.

As a new graduate, I am glad that I did not get consumed into the manual therapy and biomechanical world. It is easy to fall too far down the rabbit hole and only treat piles of tight muscles, misaligned bones, and arthritic joints. We treat human beings, along with their muscles, bones, and joints. Human beings with their own perceptions, thoughts, and fears. It is hard to go against the grain as a new grad. The therapists you work with may not have heard of Moseley, Butler, or Louw. They might look at you weirdly when you mention “pain science” or “neuroscience education.” Using pain science concepts, we have the opportunity to present a new hope to the people we treat. Don’t blow your chance.

I’m not familiar with that particular device, and would have to do a bit of research review on it to give you a complete answer. But I would assume that like most stim units/stim treatments, it probably provides temporary relief, but would not do much for long term outcomes.